Power, Fuel & Energy

     Rig Revealed     Part I     Part II

 Part III - Solar Power, Will we ever live long enough to break even?

Introduction - 12/29/2009

     No one will disagree with the importance of preserving a future rich in options to pass along to the next generation. Opinions vary widely as to how this is to be accomplished, what it should cost society, who pays and what the appropriate personal commitment levels need to be for positive change to occur. The family of man and its exploding population has had a profound impact on the planet. As a result of overcrowding we lose our freedom and junk up the planet which has fueled the environmental movement. Like so many movements that started with good intentions, environmentalism has become somewhat of a runaway thought process and a political device. This is sad because it has soured basically good intentions to so many people. Global warming isn't working so now it's been renamed climate change. It's this form of trickery that seriously dilutes credibility. Whatever term you fancy, the environment is important to all life and everyone has a stake in it. What we need are facts and when man's infinite wisdom can't produce them we resort to spraying about nebulus terms. Some believe the end is near while others think nature will endure no matter what we do. No one really knows (including the experts) how the Earth will respond to man's continued existence past, present and future. That implies it's a good idea to error on the side of caution. Remedial measures need to be tempered with practicality, good judgement and common sense. They also should be based on facts, work economically, socially and not manifest themselves as punishments for crimes committed against the Earth payable to oppressed civilizations. Bandaids, quick fixes and trends are the last things we need. I often say in times like these, three sides of the story told will include your side, my side and the facts. Greed, poor quality leadership, laziness, corruption, excessive emotionalism, radical environmentalism, fat cat governments and other forms of selfish short sighted behavior will do little to help the environment or humanity's cause. Each of us can make the decision to become part of the solution or part of the problem and acting in concert we can make a huge difference. Demonizing hard working America and other productive industrialized nations for their rich manufacturing history and problem solving genius is a useless form of finger pointing that gets everyone nowhere. If America is truly a demon why then do so many people gladly accept its money? It's a very good possibility tomorrow's solutions and funding for them will come from the industrialized nations and their people. They aren't the enemy. Energy spent on crossing social, ethnic and religious boundaries could help us form a stronger team and nurture the kinds of solutions we need. But who defines the core values, directions they take and ethics of this team? Today things are very complex which means most of us are ignorant about them in some way. Being ignorant is a normal extension of the human condition and we've all been there. You learn by doing and making mistakes in the process. But remaining ignorant or avoiding mistakes by doing nothing is a form of stupidity that we might not have time for given certain urgencies we face. Ignorant people are easily taken advantage of and led down the wrong path and thus can't put their best foot forward. The media and corrupt governments lead people down this path every day. Truth (and it does hurt sometimes) and facts are the best remedies for ignorance and offer us hope for a brighter future. As we rethink our energy strategy, solar power is being given serious consideration as an important player in securing a cleaner more sustainable future. Common sense would indicate that clean energy will come not from one all mighty solution but from a blend of many different solutions. As always, time will tell us where, when and how solar power moves off the drawing board and into the arena of clean energy sources.

      There's nothing like a discussion of money to pique people's interest is there? In this part we'll take a look at the costs associated with installing a solar system, its cost of operation and what type of return on your investment can be expected. It should be noted that money shouldn't be the only criteria to use when determining if something has value or not. Some benefits are delayed and go beyond the all mighty buck. Investing properly in the future is a good thing and it's hard to attach a cost to what a healthy future is worth. Using fuel, power and energy in smarter ways makes a lot of sense and each of us should consider more efficient methods of consumption, generation and cleanliness. That might mean choosing a smaller house, stopping at two or three kids, installing a solar system, sharing a ride or insulating better. One thing is for sure we can't just go around all the time and do whatever we damn well please. Although this presentation centers around one specific solar installation, small and large PV arrays work basically the same way. Below is a break down of the Bus-Stead components and their cost:

Bus-Stead Solar Components and Their Cost
Unit Cost
Total Cost
BP 170SX PV Solar Panels $860.00 8 $6,880.00
Lifeline 8D Deep Cycle AGM Battery $550.00 4 $2,200.00
Magnum Energy 2800W Pure Sine Wave Inverter $1,600.00 1 $1,600.00
Outback Power MX60 Solar Controller $750.00 2 $1,500.00
MC Cabling $44.00 16 $704.00
Misc Wiring, Terminal Strips, Roof Box, Etc. $500.00 1 $500.00
Total Cost of Above Components:  $13,384.00 (Does not include installation costs)

     From the table above one can see this stuff isn't cheap and it doesn't include everything that was needed to put the system into operation. At the time of this writing, the MX60 solar controller has been discontinued and replaced by another model called the MX60Flex. No effort has been made here to identify the cost of keeping the system current. I designed and made all the custom brackets, elevator poles, air foils and combiner box to get everything ready for roof top installation. A special heating system was devised to keep the brackets warm to allow the adhesive to cure. Making the parts, installing them and running the wires took hundreds of hours of work. Jeannie and I handled all of it ourselves. Every phase of this installation was custom and thwart with access difficulties and issues all of which required time to resolve. Custom beauty panels and brackets were made for things visible inside the living space. A custom battery bay monitor was also made to keep track of power into and out of the battery banks. Wires had to be run out of sight with due regard for fusing and safety. Several custom high amperage terminal blocks needed to be made as well. The effort involved produced one of the best and most powerful solar systems you'd find on any bus. The ability to tip the panels on any four sides for improved collection is unique to this type of system. If you attached a $35/hr rate to the labor we put in I guess it would be worth about $14,000.00 All that said, the system isn't perfect and has some short comings which I'll present later.

Solar Collection, Costs and Savings
Daily Power Collected*
Prevailing Power Rate 12/2009
Daily Cost
Typical Daily Usage
3KW Winter $0.10 per KW $0.30 Total 60-82KW (Cold to sub-zero climate w/electric heat)
10KW Summer $0.10 per KW $1.00 Total 1-2KW (Ideal climate no A/C)
* On a clear sunny day with no shadows cast on solar panels.  

     As you can see our power usage varies widely depending primarily on what the local climate is. Typical daily usage is the whole ball of wax and it includes everything that uses electricity in the bus. Not all shore power connections include a meter and I don't have any readings for those months we spent in AZ in 110F with two air conditioners whirling away 24x7. My guess is it would be close to the cold weather sub-zero numbers where we have two ceramic heaters whirling away 24x7. As expected extreme climates necessitate running heating or cooling which consumes power. Considerable savings can result in choosing moderate climates and many mobile people do just that. I'll update this table whence summer data becomes available. Even with missing summer numbers, the data above will give a good idea of what's going on however. The bus is small and reasonably tight so overall we use a lot less power than two people living in a full sized home.

Breaking Even on Solar
Cost of System
Daily Cost of Power Collected
Yearly Cost of Power Collected
Years to Break Even Point
$13,384.00* $1.00** $365.00 36.6 (w/battery bank)
30.6 (w/o battery bank)
* Does not include approximately $14K worth of design and installation effort.
** Most optimistic summer values.


     The data shown in the table above is almost a joke since the components themselves won't last through to the pay back date. Keep in mind the data shown are the most optimistic values and present the system in the best possible light (no pun intended). I've costed out utility power at $0.10/KW which is more expensive than it really is. You won't collect 10KW of solar power every day either owing to seasonal reductions in solar energy and cloudy days. The battery bank also has a limited service life. If one assumes the bank is good for 5 years then its cost is $36.66 per month which completely wipes out any savings associated with collecting solar power. So if you are basing your decision to install a solar system on saving money take a good look at the numbers. If you are emotionally bound to going green then it's another matter. Either way you won't live long enough to ever pay it back. Even if panel efficiencies double (and I doubt they will) it's still a long road back to the gravy watts. Solar power may be clean but all the equipment needed to collect it certainly has an impact on the environment. How green solar really is has yet to be determined because not enough systems are operating yet. Several panel constructions exist and the cells are based on one or more of the substances copper, indium, gallium, selenide, cadmium, tellurium and silicon. Large scale production of panels would require these substances to be produced first. And what is the environmental impact of this going to be? Batteries can be eliminated for grid tie systems which cuts down on system cost, lead and maintenance. But the analysis above isn't dependant on the presence or absence of a battery bank. It simply tabulates what you can collect and how long it will take to break even. Currency adjustments for inflation haven't been factored in either and they will lengthen the pay back time. If the price of power per kilowatt goes up (and it will over time) then the system pays itself back quicker. So it's a tough call to nail down exactly when the break even point will come. But it's safe to assume it's a long way out there and too long for most people. Now the federal government is meddling and tampering with the solar market by offering incentives to home owners and businesses. They are on again off again with these perks. Dumping federal money into this market gives the government a measure of control and, of course, artificially lowers the cost of a solar system. The analysis above assumes you pick up the costs yourself and they are indeed expensive. I think solutions need to work within a normal market economy less the government pumping in dollars. For solar that means figuring out ways to make systems affordable based on the power they can generate. Bringing break even points within the realm of the reasonable would be another good goal to achieve and perhaps a blast of government money helps us all on our way. The limiting factors are the panels themselves as they don't presently collect enough power to be cost effective to the average person. Solar systems need sun and if you are located out of the sun belt collection will be limited. What that does is effectively increase the cost of operating a system and beyond a certain point owning and operating a system just doesn't make any sense. When you think about solar power don't limit yourself to thinking in terms of PV arrays only. Also realize that generating electricity by harnessing the sun's energy isn't a new concept. California and Nevada have undertaken two huge solar power generation projects called Solar 1 CA and Solar 1 NV. These are solar thermal plants and aren't based on PV arrays. But power needs to be generated at night so we need an alternate source of power that doesn't use the sun. Clean coal, nuclear and hydro electric can fill the void.


     It's certainly cheaper just to buy power from your local utility. If you plan on generating it yourself via solar or a generator expect your electricity to cost significantly more. As you can see solar power is free but the cost of the equipment required to collect and manage it is expensive. Installation can be complex and expensive as well. Present PV technology doesn't provide us with an efficient means of converting solar radiation into electricity. Storing electricity via a battery bank is both expensive, bulky and inefficient. In many parts of the US, access to direct sunlight is difficult and unreliable. Even under ideal conditions expect significant seasonal changes in available solar energy. The true environmental impact of generating electricity via PV arrays on a large scale basis has yet to be determined. And PV solar may not be the green savior that you think. Better solar panels and more data are needed to answer this question. Grid tie systems eliminate the batteries and storage problems but doesn't change the physics of how PV arrays collect sunlight. Expect moderate to long pay back periods for solar systems. For home owners, choosing a smaller house and/or one that is more energy efficient might save more power than a solar system will generate. Pay back periods to these choices are immediate. Using electricity wisely can also go a long way toward saving a watt. Using compact fluorescent bulbs, turning lights off when not needed, LEDs and efficient appliances can also help. Using air conditioning systems sparingly can save huge amounts of power. Why air condition living spaces that aren't occupied.

     If you need electricity in remote areas where no power grid is available then you will need a generator. Supplementing that generator with a solar system will help reduce your dependency on fossil fuels. Solar electric is cheaper than diesel generator electricity. If you pick a moderate climate where heat and air conditioning aren't required chances are you can cover all your electricity needs with a robust solar system. But the power certainly isn't free. It might be green but it's going to be much more expensive than its utility counterpart. The Bus-Stead system costs $68/mth if you assume a 30 year life expectancy and 6 battery bank replacements over that time. Assuming 300KW/mth collected that means you'll pay about $0.23/KW which is almost 3 times the utility's rate. But if utility power isn't available it's solar, generator or sitting in the dark. As far as a generator goes, our genset would burn about $45.00 of diesel fuel ($2.50/gal) a day which is $1,350/mth for electricity. That's a pretty hefty electric bill. A diesel generator is a valuable tool but it must be used sparingly as supplemental power only. Unless a dire emergency presents itself a diesel generator isn't run constantly. Our AGM batteries can be charged very rapidly in less than 2 hours on a cloudy day. Cooking a couple of microwave meals takes 9 minutes. Running a load of laundry takes an hour. Our inverter and battery bank can handle these loads but it makes more sense to use the generator. Again this assumes you are in a remote area.

System Short Comings

     We've covered all the costs and equipment issues above. The challenge we face is efficiently using and/or storing excess solar power. Outback makes a mate unit which coordinates two or more MX60 solar controllers. We do not have this installed as of late and it would help better manage power. Being able to run the heater in the refrigerator (it's a gas absorption system) would help make better use of our solar power during the day. In the absense of electricity, the refrigerator uses propane. The trick is to examine what's coming in on solar, use what the battery bank needs and take any excess elsewhere to power active loads. Instead the solar controllers will idle if power usage is below what our solar array can collect. This is wasteful. More research and experimentation is required to better adapt the system to our needs. Luckily we don't find ourselves away from shore power very often. It would be nice if we had a grid tie inverter to offset what comes through the meter. But in campgrounds that don't sell electricity by the KW this wouldn't save us anything. So far we've been able to keep the lights on and everything running which is good. Knowing that we can sustain ourselves in the complete absence of utility power is also a comfort. I hope we never have to exercise this option for extended periods of time.